Book/Report

FZJ-2020-01142

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Untersuchungen zur Temperatur- und Absenkungsgeschichte sowie zur Bildung und Migration von Methan und molekularem Stickstoff im Nordostdeutschen Becken

Friberg, L. J. (Corresponding author)FZJ*

2001
Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag Jülich

Please use a persistent id in citations: http://hdl.handle.net/2128/24374

Report No.: Juel-3914

Abstract: The temperature- and burial history of the northern part of the Northeast German basin (Mecklenburg-Vorpommern and adjacent areas) was investigated with an interdisciplinary approach of geological, geochemicaland petrophysical methods applying the basin modelling Software PetroMode$^\circledR$. The calibration of the simulated thermal history was principally performed with organic maturity parameters(vitrinite reflectance) and borehole temperatures. For this purpose samples were collected from deep wells. Inaddition, unpublished vitrinite reflectance data from the industry and published data were taken into account.Vitrinite reflectance was measured preferentially an Carboniferous shale samples, because the organic materialwithin the Ceno-Mesozoic samples is often oxidised. In the Rügen area and in Vorpommern, vitrinite reflectanceFanges from 1.4 to 4.4%VR$_{\Gamma}$, within the Carboniferous strata. Occasionally the vitrinite reflectance data show avery strong scatter related to the distribution of magmatic rocks. During their emplacement these rocks caused anabrupt increase in temperature resulting in a rise in vitrinite reflectance in their vicinity. The measured data ofindividual Zechstein samples vary between 0.6 and 1.5%VR$_{\Gamma}$.In the basin centre the vitrinite reflectance data of the Carboniferous shales (well Parchim 1 and Pröttlin 1) rangebetween 3.1 and 5%VRVR$_{\Gamma}$. In the sedimentary Rotliegend vitrinite reflectance values are approximately at 4%VRVR$_{\Gamma}$whereas they are at 0.59%VRVR$_{\Gamma}$ in the Hettangium (well Mirow 1).In addition to the organic maturity parameters, the inorganic geo-thermometer of illite crystallinity was used.Illite crystallinity indicates diagenetic conditions in all cases. For the northern part of the study area this fact issupported by the vitrinite reflectance data. In the southern part, however, the paleo-temperatures derived fromvitrinite reflectance are higher than those documented by the illites. The retardation of the illite crystallinitycompared to vitrinite reflectance in this area was presumably due to a restricted supply of ions.For numerical simulations it was necessary to define the geologic evolution of the studied system through thegeologic past without leaving any time gaps. For a quantitative assessment of the deposited and subsequentlyeroded sediments during Upper Cretaceous through Tertiary times, the evolution of sonic velocities in shaleswith depth was analysed. The results of six wells in the study area Show that the eroded thicknesses weregenerally below 500 m. An estimation of the maximum burial depth using vitrinite reflectance data according toYAMAJI (1986) also revealed a formerly deeper burial for these wells. The highest amount of eroded thicknesswas calculated for the Rügen 4 well (>1000 m). These above-mentioned insights were directly integrated into thegeological models for the Simulation.Numerical ID-simulations were carried out for 9 wells with PetroMod$^\circledR$. The basal heat flow at the time ofmaximum depth of burial and the eroded thicknesses are the most important results. For the Mirow 1 well asatisfactory match of the calibration data could only be realised if the maximum burial depth is assumed to havebeen reached in the Upper Cretaceous. The heat flow amounted to 65 mMW/m$^{2}$ and the eroded thickness to 400 m.For all other wells a Tertiary time of maximum burial was assumed. The basal heat flow varied between 60 and74 mW/m$^{2}$ for this period.High paleo heat flow values (up to 150 mW/m$^{2}$) at the beginning of basin evolution had no influence an thepresent-day coalification pattern. The same is valid for hydrothermal events which took place in the Jurassic inparts of the basin centre. [...]

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Contributing Institute(s):

1. Publikationen vor 2000 (PRE-2000 ; Retrocat)

Research Program(s):

1. 899 - ohne Topic (POF3-899) (POF3-899)

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Database coverage:

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